Process of making sulfurized dyes.



UNITED STATES PATENT OFFICE.

BENNO HOMOLKA, OF FRANKFORT-ON-THE-MAIN, AN D RICHARD WELDE, OF HOOHST-ON- THE-MAIN GERMANY, ASSIGNORS TO FARBWERKE VORM. MEISTER LUOIUS & BRUNING, OF HOCHST-ON-THE-MAIN, GERMANY, A CORPORATION OF GERMANY.

PROCESS OF MAKING SULFURIZED DYES.

Specification of Letters Patent.

Patented July 21, 1908.

Application filed February 5, 1907. Serial No. 356,874.

O (OH) R 011 or R{ on or from their carboxylic acids having the general formula:

1 c on) (2) S 2 s it said bodies be heated with the soluble salts on-ooon,

' of thiosulfuric acid, for instance, with sodium thiosulfate, Na S O +5H O, to temperature above 100 C. v

In the above general formulas R means an aromatic residue, for instance, C IL for the hydrogen atoms of which other elements or groups may be partly'or wholly substituted.

Example 1.. 10 parts by weight of one of the above mentioned 'al ha-oxythionaphtones or of an 'alpha-oxyt iiona' hthene carboxylic acid are heated preferab y in a closed Vessel to about 100-130 Cwith 100 parts by weight of crystallized sodium sulfate ua s o 511 0.

When cold the product of reaction is extracted with water, the separated dyestuif is collected on a filter and dried. It has the following formula: C H S O The dyestuffs are red crystalline powders, insoluble in water, soluble with a green color in concentratedsulfuric acid and with a red color in chloroform; they are reduced by alkaline reducing agents and dye in the vat textile fibers a red shade.

For the sodium thiosulfate may be substituted other alkalineor alkaline earths metals. If they contain no water of crystallization, some water may be added to the mass. Having now described our invention, what we claim 1 82- 1. The process herein described for making sulfurous dyestuffs, which consists in heating alpha-oxythionapht'heneswith in water soluble thiosulfates in presence of water to temperatures above 100 Q.

2.. The process herein described for making sulfurous dyestuffs, which consists in heating alpha-oxythionaphthene-carboxylic acids with thiosulfates soluble in water in pres egce of water to temperatures above 100 In testimony, that we claim the foregoing as our invention,' we have signed our names in presence oftwo subscribing witnesses.

BENNO 'HOMOLKA. RICHARD WELDE.

Witnesses: JEAN GRUND, CARL GRUND. 

